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Transcript
Parks Division Electrical Safety Procedures The following procedures are an excerpt from the OSHA 1910.330-335 Electrical Safety regulations. Deenergizing Electrical Equipment (b) (2) (ii) Deenergizing equipment. (A) Safe procedures for deenergizing circuits and equipment shall be determined before circuits or equipment are deenergized. (b) (2) (ii) (B) The circuits and equipment to be worked on shall be disconnected from all electric energy sources. Control circuit devices, such as push buttons, selector switches, and interlocks, may not be used as the sole means for deenergizing circuits or equipment. Interlocks for electric equipment may not be used as a substitute for lockout and tagging procedures. (b) (2) (ii) (C) Stored electric energy which might endanger personnel shall be released. Capacitors shall be discharged and high capacitance elements shall be short-circuited and grounded, if the stored electric energy might endanger personnel. NOTE: If the capacitors or associated equipment are handled in meeting this requirement, they shall be treated as energized. (b) (2) (ii) (D) Stored non-electrical energy in devices that could reenergize electric circuit parts shall be blocked or relieved to the extent that the circuit parts could not be accidentally energized by the device. Lock out – Tag out (b) (2) (iii) Application of locks and tags. (A) A lock and tag shall be placed on each disconnecting means used to deenergize circuits and equipment on which work is to be performed, except as provided in paragraphs (b) (2) (iii) (C) and (b) (2) (iii) (E) of this section. The lock shall be attached so as to prevent persons from operating the disconnecting means unless they resort to undue force or the use of tools. (b) (2) (iii) (B) Each tag shall contain a statement prohibiting unauthorized operation of the disconnecting means and removal of the tag. (b) (2) (iii) (C) If a lock cannot be applied, or if the employer can demonstrate that tagging procedures will provide a level of safety equivalent to that obtained by the use of a lock, a tag may be used without a lock. Page 1 of 8 Revised 05/13/17 (b) (2) (iii) (D) A tag used without a lock, as permitted by paragraph (b) (2) (iii) (C) of this section, shall be supplemented by at least one additional safety measure that provides a level of safety equivalent to that obtained by the use of a lock. Examples of additional safety measures include the removal of an isolating circuit element, blocking of a controlling switch, or opening of an extra disconnecting device. (b) (2) (iii) (E) A lock may be placed without a tag only under the following conditions: (b) (2) (iii) (E) (1) Only one circuit or piece of equipment is deenergized and (b) (2) (iii) (E) (2) The lockout period does not extend beyond the work shift, and (b) (2) (iii) (E) (3) Employees exposed to the hazards associated with reenergizing the circuit or equipment are familiar with this procedure. Verification of deenergized condition (b) (2) (iv) Verification of deenergized condition. The requirements of this paragraph shall be met before any circuits or equipment can be considered and worked as deenergized. (b) (2) (iv) (A) The qualified person shall operate the equipment operating controls or otherwise verify that the equipment cannot be restarted. (b) (2) (iv) (B) A qualified person shall use test equipment to test the circuit elements and electrical parts of equipment to which employees will be exposed and equipment parts are deenergized. The test shall also determine if any energized condition exists as a result of inadvertently induced voltage or unrelated voltage backfeed even though specific parts of the circuit have been deenergized and presumed safe. If the circuit to be tested is over 600 volts, nominal, the test equipment shall be checked for proper operation immediately before and immediately after this test. Reenergizing Equipment (b) (2) (v) Reenergizing equipment. These requirements shall be met, in the order given, before circuits or equipment are reenergized, even temporarily. (b) (2) (v) (A) A qualified person shall conduct tests and visual inspections, as necessary, to verify that all tools, electrical jumpers, shorts, grounds, and other such devices have been removed, so that the circuits and equipment can be safely energized. (b) (2) (v) (B) Employees exposed to the hazards associated with reenergizing the circuit or equipment shall be warned to stay clear of circuits and equipment. Page 2 of 8 Revised 05/13/17 (b) (2) (v) (C) Each lock and tag shall be removed by the employee who applied it or under his or her direct supervision. However, if this employee is absent from the workplace, then the lock or tag may be removed by a qualified person designated to perform this task provided that: (b) (2) (v) (C) (1) The employer ensures that the employee who applied the lock or tag is not available at the workplace, and (b) (2) (v) (C) (2) The employer ensures that the employee is aware that the lock or tag has been removed before he or she resumes work at that workplace. (b) (2) (v) (D) There shall be a visual determination that all employees are clear of the circuits and equipment. Working on Energized Equipment (c) Working on or near energized equipment. (1) Application. This paragraph applies to work performed on exposed live parts (involving either direct contact or contact by means of tools or materials) or near enough to them for employees to be exposed to any hazard they present. (c) (2) Work on energized equipment. Only qualified persons may work on electric circuit parts or equipment that have not been deenergized under the procedures of paragraph (b) of this section. Such persons shall be capable of working safely on energized circuits and shall be familiar with the proper use of special precautionary techniques personal protective equipment, insulating and shielding materials and insulated tools. Approach Distances for Qualified Employees – Alternating Current Voltage range (phase to phase) Minimum approach distance 300V and less Avoid contact Over 300V, not over 750V 1 foot Over 750V, not over 2kV 1 foot 6 inches Over 2kv Do not get closer than 4 feet 6 inches Vehicular and Mechanical Equipment (c) (3) (iii) Vehicular and mechanical equipment. (A) Any vehicle or mechanical equipment capable of having parts of its structure elevated near energized overhead lines shall be operated so that a clearance of 10 ft. is maintained. If voltage is higher than 50kV, the clearance shall be increased 4 inches for every 10kV over that voltage. Page 3 of 8 Revised 05/13/17 Illumination (c) (4) Illumination. (I) Employees may not enter spaces containing exposed energized parts unless illumination is provided that enables the employees to perform the work safely. (c) (4) (ii) Where lack of illumination or an obstruction precludes observation of the work performed, employees may not perform tasks near exposed energized parts. Employees may not reach blindly into areas which may contain energized parts. Confined Work Space (c) (5) Confined or enclosed work spaces. When an employee works in a confined or enclosed space (such as a manhole or vault) that contains exposed energized parts, the employer shall provide, and the employee shall use protective shields, protective barriers, or insulating materials as necessary to avoid inadvertent contact with these parts. Doors, hinged panels, and the like shall be secured to prevent their swinging into an employee and causing the employee to contact exposed energized parts. Portable Ladders (c) (7) Portable ladders. Portable ladders shall have nonconductive siderails if they are used where the employee or the ladder could contact exposed energized parts. Conductive apparel (c) (8) Conductive apparel. Conductive articles of jewelry and clothing (such as watchbands, bracelets, rings, key chains, necklaces, metalized aprons, cloth with conductive thread, or metal headgear) may not be worn if they might contact exposed energized parts. However, such articles may be worn if they are rendered nonconductive by covering, wrapping, or other insulating means. Housekeeping Duties (c) (9) Housekeeping Duties. Where live parts present an electrical contact hazard, employees may not perform housekeeping duties at such close distances to the parts that there is a possibility of contact, unless adequate safeguards (such as insulating equipment or barriers) are provided. Electrically conductive cleaning materials (including conductive solids such as steel wool, metalized cloth, and silicon carbide, as well as conductive liquid solutions) may not be used in proximity to energized parts unless procedures are followed which will prevent electrical contact. Page 4 of 8 Revised 05/13/17 Interlocks (c) (10) Interlocks. Only a qualified person following the requirements of paragraph (c) of this section may defeat an electrical safety interlock, and then only temporarily while he or she is working on equipment. The interlock system shall be returned to its operable condition when this work is completed. Use of Equipment (a) Portable electric equipment. This paragraph applies to the use of cord- and plug-connected equipment, including flexible cord sets (extension cords). (a) (1) Handling. Portable equipment shall be handled in a manner, which will not cause damage. Flexible electric cords connected to equipment may not be used for raising or lowering the equipment. Flexible cords may not be fastened with staples or otherwise hung in such a fashion as could damage the outer jacket or insulation. (a) (2) Visual Inspection. Portable cord and plug-connected equipment and flexible cord sets (extension cords) shall be visually inspected before use on any shift for external defects (such as loose parts, deformed and missing pins, or damage to outer jacket or insulation) and for evidence of possible internal damage (such as pinched or crushed outer jacket). Cord- and plug-connected equipment and flexible cord sets (extension cords) which remain connected once they are put in place and are not exposed to damage need not be visually inspected until they are relocated. (a) (2) (ii) If there is a defect or evidence of damage that might expose an employee to injury, the defective or damaged item shall be removed from service, and no employee may use it until repairs and tests necessary to render the equipment safe have been made. (a) (2) (iii) When an attachment plug is to be connected to a receptacle (including any on a cord set), the relationship of the plug and receptacle contacts shall first be checked to ensure that they are of proper mating configurations. (a) (3) Grounding-type equipment. A flexible cord used with grounding-type equipment shall contain an equipment-grounding conductor. (a) (3) (ii) Attachment plugs and receptacles may not be connected or altered in a manner which would prevent proper continuity of the equipment grounding conductor at the point where plugs are attached to receptacles. Additionally, these devices may not be altered to allow the grounding pole of a plug to be inserted into slots intended for connection to the current-carrying conductors. Page 5 of 8 Revised 05/13/17 (a) (3) (iii) Adapters which interrupt the continuity of the equipment grounding connection may not be used. Electric power and lighting circuits (b) Electric power and lighting circuits. (1) Routine opening and closing of circuits. Load rated switches, circuit breakers, or other devices specifically designed as disconnecting means shall be used for the opening, reversing, or closing of circuits under load conditions. Cable connectors not of the load-break type, fuses, terminal lugs, and cable splice connections may not be used for such purposes, except in an emergency. (b) (2) Reclosing circuits after protective device operation. After a circuit is deenergized by a circuit protective device, the circuit may not be manually reenergized until it has been determined that the equipment and circuit can be safely energized. The repetitive manual reclosing of circuit breakers or reenergizing circuits through replaced fuses is prohibited. NOTE: When it can be determined from the design of the circuit and the overcurrent devices involved that the automatic operation of a device was caused by an overload rather than a fault condition, no examination of the circuit or connected equipment is needed before the circuit is reenergized. (b) (3) Overcurrent protection modification. Overcurrent protection of circuits and conductors may not be modified, even on a temporary basis, beyond that allowed by 1910.304(e), the installation safety requirements for overcurrent protection. Test Instruments and Equipment (c) Test instruments and equipment. (1) Use. Only qualified persons may perform testing work on electrical circuits or equipment. (c) (2) Visual inspection. Test instruments and equipment and all associated test leads, cables, power cords, probes, and connectors shall be visually inspected for external defects and damage before the equipment is used. If there is a defect or evidence of damaged item shall be removed from service, and no employee may use it until repairs and tests necessary to render the equipment safe have been made. (c) (3) Rating of equipment. Test instruments and equipment and their accessories shall be rated for the circuits and equipment to which they will be connected and shall be designed for the environment in which they will be used. Page 6 of 8 Revised 05/13/17 Safeguards for Personnel Protection (a) Use of protective equipment. Personal protective equipment. Employees working in areas where there are potential electrical hazards shall be provided with, and shall use, electrical protective equipment that is appropriate for the specific parts of the body to be protected and for the work to be performed. (a) (1) (ii) Protective equipment shall be maintained in a safe, reliable condition and shall be periodically inspected or tested, as required. (a) (1) (iii) If the insulating capability of protective equipment may be subject to damage during use, the insulating material shall be protected. (For example the outer covering of leather is sometimes used for the protection of rubber insulating material.) (a) (1) (iv) Employees shall wear nonconductive head protection wherever there is a danger of head injury from electric shock or burns due to contact with exposed energized parts. (a) (1) (v) Employees shall wear protective equipment for the eyes and face wherever there is danger of injury to the eyes or face from electric arcs or flashes or from flying objects resulting from electrical explosion. (a) (2) General protective equipment and tools. 9I) When working near exposed energized conductors or circuit parts, each employee shall use insulated tools or handling equipment if they might make contact with such conductors or parts. If the insulating capability of insulated tools or handling equipment is subject to damage, the insulating material shall be protected. (a) (2) (i) (A) Fuse handling equipment, insulated for circuit voltage, shall be used to remove or install fuses when the fuse terminals are energized. (a) (2) (i) (B) Ropes and handlines used near exposed energized parts shall be nonconductive. (a) (2) (ii) Protective shields, protective barriers, or insulating materials shall be used to protect each employee from shock, burns, or other electrically related injuries while that employee is working near exposed energized parts which might be accidentally contacted or where dangerous electric heating or arcing might occur. When normally enclosed live parts are exposed for maintenance or repair, they shall be guarded to protect unqualified persons from contact with the live parts. (b) Alerting techniques. The following alerting techniques shall be used to warn and protect employees from hazards which could cause injury due to electric shock, burns, or failure of electric equipment parts: Page 7 of 8 Revised 05/13/17 (b) (1) Safety signs and tags. Safety signs, safety symbols, or accident prevention tags shall be used where necessary to warn employees about electrical hazards which may endanger them. (b) (2) Barricades. Barricades shall be used in conjunction with safety signs where its is necessary to prevent or limit employee access to work areas exposing employees to uninsulated energized conductors or circuit parts. Conductive barricades may not be used where they might cause an electrical contact hazard. (b) (3) Attendants. If signs and barricades do not provide sufficient warning and protection from electrical hazards, an attendant shall be stationed to warn and protect employees. Qualified Electrical Worker Qualified Electrical Worker – is defined as one familiar with the construction and operation of the equipment and hazards involved. An employee who is undergoing on-the-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person is considered to be a qualified person for the performance of those duties. When a person has successfully demonstrated their full knowledge and understanding of the Maintenance Division Electrical Safety Procedures, a written document of qualification will be placed in their personnel file. Page 8 of 8 Revised 05/13/17